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2019-05-03powerpc/hmi: Fix kernel hang when TB is in error state.Mahesh Salgaonkar
On TOD/TB errors timebase register stops/freezes until HMI error recovery gets TOD/TB back into running state. On successful recovery, TB starts running again and udelay() that relies on TB value continues to function properly. But in case when HMI fails to recover from TOD/TB errors, the TB register stay freezed. With TB not running the __delay() function keeps looping and never return. If __delay() is called while in panic path then system hangs and never reboots after panic. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/entry: Remove unneeded need_resched() loopValentin Schneider
Since the enabling and disabling of IRQs within preempt_schedule_irq() is contained in a need_resched() loop, we don't need the outer arch code loop. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> [mpe: Rebase since CURRENT_THREAD_INFO() removal] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/prom_init: get rid of PROM_SCRATCH_SIZEChristophe Leroy
PROM_SCRATCH_SIZE is same as sizeof(prom_scratch) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/security: Show powerpc_security_features in debugfsMichael Ellerman
This can be helpful for debugging problems with the security feature flags, especially on guests where the flags come from the hypervisor via an hcall and so can't be observed in the device tree. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/64: Don't trace code that runs with the soft irq mask unreconciledNicholas Piggin
"Reconciling" in terms of interrupt handling, is to bring the soft irq mask state in to synch with the hardware, after an interrupt causes MSR[EE] to be cleared (while the soft mask may be enabled, and hard irqs not marked disabled). General kernel code should not be called while unreconciled, because local_irq_disable, etc. manipulations can cause surprising irq traces, and it's fragile because the soft irq code does not really expect to be called in this situation. When exiting from an interrupt, MSR[EE] is cleared to prevent races, but soft irq state is enabled for the returned-to context, so this is now an unreconciled state. restore_math is called in this state, and that can be ftraced, and the ftrace subsystem disables local irqs. Mark restore_math and its callees as notrace. Restore a sanity check in the soft irq code that had to be disabled for this case, by commit 4da1f79227ad4 ("powerpc/64: Disable irq restore warning for now"). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/irq: drop __irq_offset_valueChristophe Leroy
This patch drops__irq_offset_value which has not been used since commit 9c4cb8251513 ("powerpc: Remove use of CONFIG_PPC_MERGE") This removes a sparse warning. Fixes: 9c4cb8251513 ("powerpc: Remove use of CONFIG_PPC_MERGE") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/setup: replace ifdefs by IS_ENABLED() wherever possible.Christophe Leroy
Compared to ifdefs, IS_ENABLED() provide a cleaner code and allows to detect compilation failure regardless of the selected options. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/setup: cleanup the #ifdef CONFIG_TAU blockChristophe Leroy
Use cpu_has_feature() instead of opencoding Use IS_ENABLED() instead of #ifdef for CONFIG_TAU_AVERAGE Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/setup: cleanup ifdef mess in check_cache_coherency()Christophe Leroy
Use IS_ENABLED() instead of #ifdefs Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/setup: Remove unnecessary #ifdef CONFIG_ALTIVECChristophe Leroy
CPU_FTR_ALTIVEC is only set when CONFIG_ALTIVEC is selected, so the ifdef is unnecessary. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/mm: define an empty mm_iommu_init()Christophe Leroy
To avoid ifdefs, define a empty static inline mm_iommu_init() function when CONFIG_SPAPR_TCE_IOMMU is not selected. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/fadump: define an empty fadump_cleanup()Christophe Leroy
To avoid #ifdefs, define an static inline fadump_cleanup() function when CONFIG_FADUMP is not selected Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Don't add dummy frames when calling trace_hardirqs_on/offChristophe Leroy
No need to add dummy frames when calling trace_hardirqs_on or trace_hardirqs_off. GCC properly handles empty stacks. In addition, powerpc doesn't set CONFIG_FRAME_POINTER, therefore __builtin_return_address(1..) returns NULL at all time. So the dummy frames are definitely unneeded here. In the meantime, avoid reading memory for loading r1 with a value we already know. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: don't do syscall stuff in transfer_to_handlerChristophe Leroy
As syscalls are now handled via a fast entry path, syscall related actions can be removed from the generic transfer_to_handler path. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: implement fast entry for syscalls on BOOKEChristophe Leroy
This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: implement fast entry for syscalls on non BOOKEChristophe Leroy
This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. The overall series improves null_syscall selftest by 12,5% on an 83xx and by 17% on a 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc: Fix 32-bit handling of MSR_EE on exceptionsChristophe Leroy
[text mostly copied from benh's RFC/WIP] ppc32 are still doing something rather gothic and wrong on 32-bit which we stopped doing on 64-bit a while ago. We have that thing where some handlers "copy" the EE value from the original stack frame into the new MSR before transferring to the handler. Thus for a number of exceptions, we enter the handlers with interrupts enabled. This is rather fishy, some of the stuff that handlers might do early on such as irq_enter/exit or user_exit, context tracking, etc... should be run with interrupts off afaik. Generally our handlers know when to re-enable interrupts if needed. The problem we were having is that we assumed these interrupts would return with interrupts enabled. However that isn't the case. Instead, this patch changes things so that we always enter exception handlers with interrupts *off* with the notable exception of syscalls which are special (and get a fast path). Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: get rid of COPY_EE in exception entryChristophe Leroy
EXC_XFER_TEMPLATE() is not called with COPY_EE anymore so we can get rid of copyee parameters and related COPY_EE and NOCOPY macros. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Enter exceptions with MSR_EE unsetChristophe Leroy
All exceptions handlers know when to reenable interrupts, so it is safer to enter all of them with MSR_EE unset, except for syscalls. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: enter syscall with MSR_EE inconditionaly setChristophe Leroy
syscalls are expected to be entered with MSR_EE set. Lets make it inconditional by forcing MSR_EE on syscalls. This patch adds EXC_XFER_SYS for that. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/fsl_booke: ensure SPEFloatingPointException() reenables interruptsChristophe Leroy
SPEFloatingPointException() is the only exception handler which 'forgets' to re-enable interrupts. This patch makes sure it does. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/40x: Refactor exception entry macros by using head_32.hChristophe Leroy
Refactor exception entry macros by using the ones defined in head_32.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/40x: Split and rename NORMAL_EXCEPTION_PROLOGChristophe Leroy
This patch splits NORMAL_EXCEPTION_PROLOG in the same way as in head_8xx.S and head_32.S and renames it EXCEPTION_PROLOG() as well to match head_32.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/40x: add exception frame markerChristophe Leroy
This patch adds STACK_FRAME_REGS_MARKER in the stack at exception entry in order to see interrupts in call traces as below: [ 0.013964] Call Trace: [ 0.014014] [c0745db0] [c007a9d4] tick_periodic.constprop.5+0xd8/0x104 (unreliable) [ 0.014086] [c0745dc0] [c007aa20] tick_handle_periodic+0x20/0x9c [ 0.014181] [c0745de0] [c0009cd0] timer_interrupt+0xa0/0x264 [ 0.014258] [c0745e10] [c000e484] ret_from_except+0x0/0x14 [ 0.014390] --- interrupt: 901 at console_unlock.part.7+0x3f4/0x528 [ 0.014390] LR = console_unlock.part.7+0x3f0/0x528 [ 0.014455] [c0745ee0] [c0050334] console_unlock.part.7+0x114/0x528 (unreliable) [ 0.014542] [c0745f30] [c00524e0] register_console+0x3d8/0x44c [ 0.014625] [c0745f60] [c0675aac] cpm_uart_console_init+0x18/0x2c [ 0.014709] [c0745f70] [c06614f4] console_init+0x114/0x1cc [ 0.014795] [c0745fb0] [c0658b68] start_kernel+0x300/0x3d8 [ 0.014864] [c0745ff0] [c00022cc] start_here+0x44/0x98 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/40x: Don't use SPRN_SPRG_SCRATCH2 in EXCEPTION_PROLOGChristophe Leroy
Unlike said in the comment, r1 is not reused by the critical exception handler, as it uses a dedicated critirq_ctx stack. Decrementing r1 early is then unneeded. Should the above be valid, the code is crap buggy anyway as r1 gets some intermediate values that would jeopardise the whole process (for instance after mfspr r1,SPRN_SPRG_THREAD) Using SPRN_SPRG_SCRATCH2 to save r1 is then not needed, r11 can be used instead. This avoids one mtspr and one mfspr and makes the prolog closer to what's done on 6xx and 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: make the 6xx/8xx EXC_XFER_TEMPLATE() similar to the 40x/booke oneChristophe Leroy
6xx/8xx EXC_XFER_TEMPLATE() macro adds a i##n symbol which is unused and can be removed. 40x and booke EXC_XFER_TEMPLATE() macros takes msr from the caller while the 6xx/8xx version uses only MSR_KERNEL as msr value. This patch modifies the 6xx/8xx version to make it similar to the 40x and booke versions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: move LOAD_MSR_KERNEL() into head_32.h and use itChristophe Leroy
As preparation for using head_32.h for head_40x.S, move LOAD_MSR_KERNEL() there and use it to load r10 with MSR_KERNEL value. In the mean time, this patch modifies it so that it takes into account the size of the passed value to determine if 'li' can be used or if 'lis/ori' is needed instead of using the size of MSR_KERNEL. This is done by using gas macro. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.SChristophe Leroy
EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/mm: print hash info in a helperChristophe Leroy
Reduce #ifdef mess by defining a helper to print hash info at startup. In the meantime, remove the display of hash table address to reduce leak of non necessary information. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32s: set up an early static hash table for KASAN.Christophe Leroy
KASAN requires early activation of hash table, before memblock() functions are available. This patch implements an early hash_table statically defined in __initdata. During early boot, a single page table is used. For hash32, when doing the final init, one page table is allocated for each PGD entry because of the _PAGE_HASHPTE flag which can't be common to several virt pages. This is done after memblock get available but before switching to the final hash table, otherwise there are issues with TLB flushing due to the shared entries. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32s: move hash code patching out of MMU_init_hw()Christophe Leroy
For KASAN, hash table handling will be activated early for accessing to KASAN shadow areas. In order to avoid any modification of the hash functions while they are still used with the early hash table, the code patching is moved out of MMU_init_hw() and put close to the big-bang switch to the final hash table. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Add KASAN supportChristophe Leroy
This patch adds KASAN support for PPC32. The following patch will add an early activation of hash table for book3s. Until then, a warning will be raised if trying to use KASAN on an hash 6xx. To support KASAN, this patch initialises that MMU mapings for accessing to the KASAN shadow area defined in a previous patch. An early mapping is set as soon as the kernel code has been relocated at its definitive place. Then the definitive mapping is set once paging is initialised. For modules, the shadow area is allocated at module_alloc(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc: disable KASAN instrumentation on early/critical files.Christophe Leroy
All files containing functions run before kasan_early_init() is called must have KASAN instrumentation disabled. For those file, branch profiling also have to be disabled otherwise each if () generates a call to ftrace_likely_update(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: use memset() instead of memset_io() to zero BSSChristophe Leroy
Since commit 400c47d81ca38 ("powerpc32: memset: only use dcbz once cache is enabled"), memset() can be used before activation of the cache, so no need to use memset_io() for zeroing the BSS. Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc: don't use direct assignation during early boot.Christophe Leroy
In kernel/cputable.c, explicitly use memcpy() instead of *y = *x; This will allow GCC to replace it with __memcpy() when KASAN is selected. Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/prom_init: don't use string functions from lib/Christophe Leroy
When KASAN is active, the string functions in lib/ are doing the KASAN checks. This is too early for prom_init. This patch implements dedicated string functions for prom_init, which will be compiled in with KASAN disabled. Size of prom_init before the patch: text data bss dec hex filename 12060 488 6960 19508 4c34 arch/powerpc/kernel/prom_init.o Size of prom_init after the patch: text data bss dec hex filename 12460 488 6960 19908 4dc4 arch/powerpc/kernel/prom_init.o This increases the size of prom_init a bit, but as prom_init is in __init section, it is freed after boot anyway. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc: remove CONFIG_CMDLINE #ifdef messChristophe Leroy
This patch makes CONFIG_CMDLINE defined at all time. It avoids having to enclose related code inside #ifdef CONFIG_CMDLINE Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc: prepare string/mem functions for KASANChristophe Leroy
CONFIG_KASAN implements wrappers for memcpy() memmove() and memset() Those wrappers are doing the verification then call respectively __memcpy() __memmove() and __memset(). The arches are therefore expected to rename their optimised functions that way. For files on which KASAN is inhibited, #defines are used to allow them to directly call optimised versions of the functions without going through the KASAN wrappers. See commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") for details. Other string / mem functions do not (yet) have kasan wrappers, we therefore have to fallback to the generic versions when KASAN is active, otherwise KASAN checks will be skipped. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Fixups to keep selftests working] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Move early_init() in a separate fileChristophe Leroy
In preparation of KASAN, move early_init() into a separate file in order to allow deactivation of KASAN for that function. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/mm: move hugetlb_disabled into asm/hugetlb.hChristophe Leroy
No need to have this in asm/page.h, move it into asm/hugetlb.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/mm: fix erroneous duplicate slb_addr_limit initChristophe Leroy
Commit 67fda38f0d68 ("powerpc/mm: Move slb_addr_linit to early_init_mmu") moved slb_addr_limit init out of setup_arch(). Commit 701101865f5d ("powerpc/mm: Reduce memory usage for mm_context_t for radix") brought it back into setup_arch() by error. This patch reverts that erroneous regress. Fixes: 701101865f5d ("powerpc/mm: Reduce memory usage for mm_context_t for radix") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/tm: Avoid machine crash on rt_sigreturn()Breno Leitao
There is a kernel crash that happens if rt_sigreturn() is called inside a transactional block. This crash happens if the kernel hits an in-kernel page fault when accessing userspace memory, usually through copy_ckvsx_to_user(). A major page fault calls might_sleep() function, which can cause a task reschedule. A task reschedule (switch_to()) reclaim and recheckpoint the TM states, but, in the signal return path, the checkpointed memory was already reclaimed, thus the exception stack has MSR that points to MSR[TS]=0. When the code returns from might_sleep() and a task reschedule happened, then this task is returned with the memory recheckpointed, and CPU MSR[TS] = suspended. This means that there is a side effect at might_sleep() if it is called with CPU MSR[TS] = 0 and the task has regs->msr[TS] != 0. This side effect can cause a TM bad thing, since at the exception entrance, the stack saves MSR[TS]=0, and this is what will be used at RFID, but, the processor has MSR[TS] = Suspended, and this transition will be invalid and a TM Bad thing will be raised, causing the following crash: Unexpected TM Bad Thing exception at c00000000000e9ec (msr 0x8000000302a03031) tm_scratch=800000010280b033 cpu 0xc: Vector: 700 (Program Check) at [c00000003ff1fd70] pc: c00000000000e9ec: fast_exception_return+0x100/0x1bc lr: c000000000032948: handle_rt_signal64+0xb8/0xaf0 sp: c0000004263ebc40 msr: 8000000302a03031 current = 0xc000000415050300 paca = 0xc00000003ffc4080 irqmask: 0x03 irq_happened: 0x01 pid = 25006, comm = sigfuz Linux version 5.0.0-rc1-00001-g3bd6e94bec12 (breno@debian) (gcc version 8.2.0 (Debian 8.2.0-3)) #899 SMP Mon Jan 7 11:30:07 EST 2019 WARNING: exception is not recoverable, can't continue enter ? for help [c0000004263ebc40] c000000000032948 handle_rt_signal64+0xb8/0xaf0 (unreliable) [c0000004263ebd30] c000000000022780 do_notify_resume+0x2f0/0x430 [c0000004263ebe20] c00000000000e844 ret_from_except_lite+0x70/0x74 --- Exception: c00 (System Call) at 00007fffbaac400c SP (7fffeca90f40) is in userspace The solution for this problem is running the sigreturn code with regs->msr[TS] disabled, thus, avoiding hitting the side effect above. This does not seem to be a problem since regs->msr will be replaced by the ucontext value, so, it is being flushed already. In this case, it is flushed earlier. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/powernv/mce: Print additional information about MCE error.Mahesh Salgaonkar
Print more information about MCE error whether it is an hardware or software error. Some of the MCE errors can be easily categorized as hardware or software errors e.g. UEs are due to hardware error, where as error triggered due to invalid usage of tlbie is a pure software bug. But not all the MCE errors can be easily categorize into either software or hardware. There are errors like multihit errors which are usually result of a software bug, but in some rare cases a hardware failure can cause a multihit error. In past, we have seen case where after replacing faulty chip, multihit errors stopped occurring. Same with parity errors, which are usually due to faulty hardware but there are chances where multihit can also cause an parity error. Such errors are difficult to determine what really caused it. Hence this patch classifies MCE errors into following four categorize: 1. Hardware error: UE and Link timeout failure errors. 2. Probable hardware error (some chance of software cause) SLB/ERAT/TLB Parity errors. 3. Software error Invalid tlbie form. 4. Probable software error (some chance of hardware cause) SLB/ERAT/TLB Multihit errors. Sample output: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable Software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/powernv/mce: Print correct severity for MCE error.Mahesh Salgaonkar
Currently all machine check errors are printed as severe errors which isn't correct. Print soft errors as warning instead of severe errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/powernv/mce: Reduce MCE console logs to lesser lines.Mahesh Salgaonkar
Also add cpu number while displaying MCE log. This will help cleaner logs when MCE hits on multiple cpus simultaneously. Before the changes the MCE output was: Severe Machine check interrupt [Recovered] NIP [d00000000ba80280]: insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ba80280 After this patch series changes the MCE output will be: MCE: CPU80: machine check (Warning) Host SLB Multihit [Recovered] MCE: CPU80: NIP: [d00000000b550280] insert_slb_entry.constprop.0+0x278/0x2c0 [mcetest_slb] MCE: CPU80: Probable software error (some chance of hardware cause) UE in host application: MCE: CPU48: machine check (Severe) Host UE Load/Store DAR: 00007fffc6079a80 paddr: 0000000f8e260000 [Not recovered] MCE: CPU48: PID: 4584 Comm: find NIP: [0000000010023368] MCE: CPU48: Hardware error and for MCE in Guest: MCE: CPU80: machine check (Warning) Guest SLB Multihit DAR: 000001001b6e0320 [Recovered] MCE: CPU80: PID: 24765 Comm: qemu-system-ppc Guest NIP: [00007fffa309dc60] MCE: CPU80: Probable software error (some chance of hardware cause) Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc: Add doorbell tracepointsAnton Blanchard
When analysing sources of OS jitter, I noticed that doorbells cannot be traced. Signed-off-by: Anton Blanchard <anton@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/64s: Remove 'dummy_copy_buffer'Mathieu Malaterre
In commit 2bf1071a8d50 ("powerpc/64s: Remove POWER9 DD1 support") the function __switch_to remove usage for 'dummy_copy_buffer'. Since it is not used anywhere else, remove it completely. This remove the following warning: arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/cacheinfo: Fix kobject memleakTobin C. Harding
Currently error return from kobject_init_and_add() is not followed by a call to kobject_put(). This means there is a memory leak. Add call to kobject_put() in error path of kobject_init_and_add(). Signed-off-by: Tobin C. Harding <tobin@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/vdso: Drop unnecessary cc-ldoptionNick Desaulniers
Towards the goal of removing cc-ldoption, it seems that --hash-style= was added to binutils 2.17.50.0.2 in 2006. The minimal required version of binutils for the kernel according to Documentation/process/changes.rst is 2.20. Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
Merge our topic branch shared with KVM. In particular this includes the rewrite of the idle code into C.